hmmm...I just orderd a presonus firebox.It has a bunch of in's and out's connecting to the computer by firewire.It had great reviews and its faster than any USB interface.

Then you can either mic your amp or buy an effects processor...obviously,micing your amp is cheaper(depending on what mic you want).I have a GT-8 for effects so,i'm going to mic my amp,but if your amp sounds lousy then theres no point in mic'ing it up.Then it would be fine to just get a POD or something.